Roll

ABSTRACT

A roll for use in a machine for at least one of producing, processing and finishing a fibrous web such as a paper, cardboard or tissue web; comprising a roll core, a roll cover arranged on the roll core, roll caps which close off the roll at its end faces, and at least one glass fiber with sensors for determining operating parameters arranged in at least one of the roll cover and between the roll cover and the roll core; whereby the at least one glass fiber is connected to an evaluation device outside the roll; and wherein the at least one glass fiber is arranged in a reversibly closable bore in the roll core and in a recess in the roll cap aligned with the reversibly closable bore.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of PCT application No. PCT/EP2014/055791, entitled “ROLL”, filed Mar. 24, 2014, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a roll for a machine for producing, processing and/or finishing a fibrous web such as a paper, cardboard or tissue web.

2. Description of the Related Art

Rolls are provided in many locations in machines for the production of paper and other web materials. They serve various purposes, for example dewatering, smoothing, rerouting and guiding of the fibrous web. In many locations the rolls are equipped with a sensor system in order to determine operating parameters of the machine and to input automatic control into the process control system.

Such sensor systems are generally in the form of sensors that are embedded in a roll cover or in the region of same. The sensors may for example be glass fibers which are inscribed with Bragg grating that are reflective for light coupled into the glass fiber. Processing of the measured data recorded by the sensors occurs in an evaluation device that is connected with the sensors. The evaluation device is arranged on an end cap of the roll and rotates with same. Alternatively it can be located separately from the roll.

A system for the determination of the pressure profile in a roll nip is known from EP 0809570 B1, including a first roll which is designed so that it forms a roll nip together with at least one additional roll, whereby the first roll includes several sensors at circumferential and axial locations around the roll in order to capture the pressurization upon the first roll when the first roll is pressed, rotating against the at least one additional roll. The sensors supply pressure signals which are representative of the pressure that is captured by each sensor. Moreover a computer is provided with a micro-processor in order to calculate values from the pressure signals of the pressure captured by at least one of the sensors, and a display that is connected with the computer in order to provide a visual illustration of the pressure measurements. The at least one sensor is a fiber optic sensor including one optical fiber that is arranged along the length of the first roll and parallel to the axis of the roll.

In order to couple the light and again channel it out, it is necessary in each case to arrange the glass fiber such that it is led out of the roll cover without it being damaged or even cut during manufacture or rework of same.

Rubber or polyurethane roll covers which are suitable for application with such sensors are normally produced oversized so that the roll cover protrudes beyond a roll core and can then be trimmed to the desired measurement. With this approach, a glass fiber that is arranged in the cover or on the boundary interface between the cover and the core would be cut.

The current state of the art does not provide any information hereto, since normally only the electrical contacting is described, whereas the connection of the fiber to the outside is not described in detail.

SUMMARY OF THE INVENTION

It is the objective of the current invention to provide measures that protect the glass fiber during production of the roll cover from damage or severing, and to arrange said glass fiber such that access for connection of external equipment is still ensured.

The invention provides that at least one glass fiber is arranged in a reversibly closable bore in the roll casing and in the recess aligned therewith in the roll cap. This ensures simple, non-destructive—even multiple—assembly and disassembly, which also offers protection from environmental influences such as heat and moisture which could damage the glass fiber.

Provision should preferably be made that the bore and the recess are dimensioned such that a fiber plug that is arranged terminally on the glass fiber can be inserted into the bore and the recess. In spite of this, the dimensioning is then still small enough as not to affect the stability of the involved roll components.

An extension cable can then easily be connected to the fiber plug.

A bore hole can preferably be incorporated in the roll cover, wherein at least one of the glass fibers is arranged, leading out of the roll cover, extending in the roll casing and feeding into the bore. In this location the glass fiber is protected and positioned without significant curvature.

In an additional embodiment, it may be provided that a sleeve is arranged in the bore in which the fiber plug is fastened, preferably screwed in.

In another embodiment, the bore and/or the recess can be provided, at least in sections with a thread.

It is to be emphasized that it is especially advantageous that the recess can be sealed gas-tight by a screw during a tempering process of the roll. The glass fiber and the fiber plug are thus optimally protected during the heat and water vapor-involving curing process from the effects of said influences.

After completion of the tempering process the screw can advantageously be replaced by a banjo bolt through which the at least one glass fiber can be led out of the roll. This renders the assembly and disassembly very simple and damage-proof.

According to preferred aspects of the invention, the roll cover can consist at least partially of rubber or polyurethane or a combination thereof, or with a fiber composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates a schematized view of the end of a roll according to the invention with one glass fiber and one passage for same, before a tempering process; and

FIG. 2 illustrates a schematized view as shown in FIG. 1, in a sectional view of the region of the passage after the tempering process.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a simplified illustration of a roll 1 for use in a machine for the production, processing and/or finishing of a fibrous web; for example a paper, cardboard or tissue web. Roll 1 includes a roll core 2 which can consist of metal or a composite material and a roll cover 3 arranged thereupon which consists of an elastic material such as rubber or polyurethane.

Roll cover 3 is normally attached to roll core 2 by way of an adhesion promoting layer or a base layer.

In known sensor systems for the determination of operating parameters in a machine for the production of a fibrous web, glass fibers 4 can be embedded into roll cover 3 or at a boundary interface between roll core 2 and roll cover 3.

When embedding glass fibers 4 into roll cover 3, glass fiber 4 must be directed laterally through roll core 2 to a roll end face 5 in order to prevent glass fiber 4 being severed and thus destroyed when trimming roll cover 3.

A bore at an approximate angle of 45° is implemented through roll cover 3 and roll core 2 into which then a protective hose is inserted that is cut off flush at its exit point from the cover, which however protrudes up to 2 m at roll end face 5. Glass fiber 4 is threaded into this hose (starting with the fiber end) and pulled through until a terminal fiber plug reaches the end of the protective hose at roll end face 5. Depending on the selected design, glass fiber 4 is then for example wound onto roll cover 3 and fastened before an additional cover layer is applied over it.

A disadvantage with this system is in particular that a roll cap 6 can no longer be removed after insertion of glass fiber 4 without destroying said glass fiber during the process. This would necessitate a completely new cover on roll 1 if the sensor technology is still to be used. This is particularly problematic for suction rolls and zone-controlled rolls since roll caps 6 must be opened more frequently with these type of rolls.

The current state of the art cannot offer any suggestions for a remedy of the problem, since always only the electrical contacting of the sensors is described. An electrical contacting is possible and has been established for a long time through simple multiple opening and closing, for example via plug-in contacts. The reliable contacting and respectively leading glass fiber 4 out of roll 1 is in contrast a challenge that is not to be underestimated, since the contacting is only possible one time when inserting glass fiber 4 into roll 1. Multiple connecting and disconnecting is not possible, so that breaking of glass fiber 4 automatically results in a complete loss of roll cover 3 including glass fiber 4. Based on the cost for a new cover with embedding of a measuring system, this is to be avoided at all cost. A simple and reliable solution for this problem is offered below.

Moreover, in addition to the general leading out and contacting of glass fiber 4, the use of in particular rubber roll cover 3 is problematic: vulcanization of rubber uses water vapor for energy transfer, representing a critical factor that attacks glass fiber 4 and leads to brittleness. This can also destroy glass fiber 4. Since vulcanization with water vapor is a proven method in the production of rubber covers it, is meaningful not to change the process, but instead to develop a protection system for glass fiber 4.

In order to protect glass fiber 4 against water vapor a gas-tight system must be realized. According to the invention, this is combined with a mechanical system that allows roll cap 6 to be opened without destroying glass fiber 4.

With reference to FIG. 2 and continued reference to FIG. 1, for this purpose a bore 7 is introduced in roll core 2 at the transition to roll cap 6 and parallel to roll cover 3 that is large enough to accommodate a fiber plug 8 and to be able to connect same manually to an extension cable 9. The diameter of bore 7 is approximately 13 to 19 mm. The transfer of glass fiber 4 from roll cover 3 occurs through a bore hole 10 that progresses in a diameter of approximately 5 mm diagonally out of roll cover 3 into roll core 2 and ends in bore 7 while avoiding strong curvature.

Glass fiber 4 is protected in borehole 10 either by a retractable protective hose that has the same dimensions as bore hole 10, or by a sheathing of glass fiber 4. In bore 7 in roll core 2 a sleeve 11 is arranged, preferable screwed in, into which fiber plug 8 is screwed at the exit from bore hole 10. Glass fiber 4 is inserted into bore hole 10 with some clearance in order to compensate for possible expansions during the tempering process.

The assembly occurs while roll cap 6 is removed from roll core 2. For tempering of roll cover 3, roll cap 6 is reattached. In the location where bore 7 has been applied in roll core 2 it has a recess 12 that is consistent with the dimensions of bore 7 in roll core 2. Recess 12 in roll cap 6 as well as the first millimeters of bore 7 in roll core 2 are equipped with a thread 13, so that a screw 14 can be screwed in from the outside whose threads can be provided additionally with a sealing adhesive in order to be able to seal bore 7 gas-tight. In addition a sealing ring that is not illustrated may be provided between roll cap 6 and roll core 2. Roll 1 thus becomes gas-tight in this region and glass fiber 4 is protected from the effects of water vapor.

After tempering, screw 14 is replaced by a banjo bolt 15 as illustrated in FIG. 2. Extension cable 9 that is designed as a sheathed glass fiber 4 is guided through the banjo bolt and connected to the permanently mounted fiber plug 8 in roll core 2. For this purpose extension cable 9 is first threaded through banjo bolt 15 and connected on sleeve 11 in roll core 2, before banjo bolt 15 is screwed into roll cap 6. The hole in banjo bolt 15 is closed by a sealing material, such as silicone, however in a way that the fiber still has some clearance. The end of extension cable 9 that is not illustrated in further detail can now be connected to an evaluation device that is also not illustrated in further detail and that is mounted for example on the roll end face 5 on roll cap 6. Extension cable 9 is attached for this purpose on roll end face 5, inserted into the evaluation device and is also attached there. Sheathed glass fiber 4 always has some clearance to allow disassembly.

For disassembly of roll cap 6 the attachments of sheathed glass fiber 4 are now simply loosened, the sealing material in banjo bolt 15 removed if necessary, banjo bolt 15 screwed out and extension cable 9 disconnected from fiber plug 8 in roll core 2. Roll cap 6 can now be easily removed without destroying glass fiber 4.

While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. 

What is claimed is:
 1. A roll for use in a machine for at least one of producing, processing and finishing a fibrous web, said roll comprising: a roll core; a roll cover arranged on the roll core; roll caps which close off the roll at its end faces; and at least one glass fiber with sensors for determining operating parameters arranged in at least one of the roll cover and between the roll cover and the roll core, whereby the at least one glass fiber is connected to an evaluation device outside the roll, wherein the at least one glass fiber is arranged in a reversibly closable bore in the roll core, and in a recess in the roll cap aligned with the reversibly closable bore.
 2. The roll according to claim 1, wherein the reversibly closable bore and the recess are dimensioned such that a fiber plug that is arranged terminally on the at least one glass fiber can be inserted into the reversibly closed bore and the recess.
 3. The roll according to claim 2, wherein an extension cable can be connected to the fiber plug.
 4. The roll according to claim 1, wherein a bore hole is incorporated in the roll cover, whereby the at least one glass fiber is arranged leading out of the roll cover, extending in the roll core and feeding into the reversibly closable bore.
 5. The roll according to claim 2, wherein a sleeve is arranged in the reversibly closable bore in which the fiber plug is fastened, preferably by being screwed in.
 6. The roll according to claim 1, wherein at least one of the reversibly closable bore and the recess are provided, at least in sections, with a thread.
 7. The roll according to claim 1, wherein the recess is sealed gas-tight by a screw during a tempering process of the roll.
 8. The roll according to claim 7, wherein after completion of the tempering process, the screw is replaceable by a banjo bolt through which the at least one glass fiber can be led out of the roll.
 9. The roll according to claim 1, wherein the roll cover consists at least partially of rubber or polyurethane or combinations thereof, or with fiber composite materials. 